Clock with temperature alarm mechanism

ABSTRACT

An otherwise conventional electric clock driven by a synchronous motor having an alarm vibrator mounted for vibration in the magnetic field of the motor and normally restrained against vibration by a bi-metal, temperature responsive element which, upon a predetermined increase in ambient temperature, pulls away from the vibrator and allows the alarm to sound.

United States Patent Nyberg [451 July 24, 1973 CLOCK WITH TEMPERATURE ALARM MECHANISM Ernest W. Nyberg, 1802 N. Damen Ave., Chicago, Ill. 60647 Filed: Nov. 17, 1971 Appl. No.: 199,502

Inventor:

US. l. 58/152 R, 58/19 R, 58/38, 340/220 Int. Cl.. G04c 21/16, G04c 47/00, G070 46/06 Field of Search 58/19, 22.5, 38, 58/145 R, 152 R, 152 A, 152 B; 116/101, 114.5; 340/220, 227.1

References Cited UNITED STATES PATENTS 10/1971 Zimmet 340/224 3,440,813 4/1969 Kolodzies 58/19 R 3,440,814 4/1969 Reimann 58/19 R 2,552,331 5/1951 Lamb; 1 58/152 R X 596,680 1/1898 Howe 340/220 3,315,462 4/1967 Bosquet 58/16 X Primary Examiner-Richard B. Wilkinson Assistant Examiner-Edith C. S. Jackmon Attorney-Wolfe, Hubbard, Leydig, Voit & Osann [57] ABSTRACT An otherwise conventional electric clock driven by a synchronous motor having an alarm vibrator mounted for vibration in the magnetic field of the motor and normally restrained against vibration by a bi-metal, temperature responsive element which, upon a predetermined increase in ambient temperature, pulls away from the vibrator and allows the alarm to sound.

1 Claim, 3 Drawing Figures CLOCK WITII TEMPERATURE ALARM MECHANISM DESCRIPTION OF THE INVENTION This invention relates generally to fire, i.e., high temperature, alarm systems and more particularly concerns adapting an otherwise conventional electric clock for a tire alarm function.

Although the need has always existed, few private homes or apartments are equipped with fire detection and alarm systems. This has probably been because such systems have been relatively expensive, troublesome. to install and subject to maintenance problems.

It is the aim of the present invention to provide simple and economical mechanism for converting an otherwise conventional electric clock into a high temperature, or fire, alarm device. Thus, any electric clcok whether wall hung, built-in, mounted in a case suitable for any room or decor, alarm type or not, can be made into an effective audible fire alarm.

Another object is to provide a clock and mechanism of the above character in which the alarm is automatically resetting and well suited for being made responsive to relatively low temperatures indicating some abnormality which, when corrected, again disables the alarm.

i It is also an object to provide a clock and mechanism of the kind described above which goes into service merely upon plugging in the conventional clock cord to a suitable electric outlet. The alarm is therefore easy to install and quite portable, permitting its owner to use it in hotels and similar temporary accommodations.

Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which: FIG. 1 is a perspective view of a clock embodying the alarm invention; FIG. 2 is a perspective of the mechanism contained within the clock shown in FIG. l; and,FlG. 3 is a rear elevation of the mechanism appearing in FIG. 2.

While the invention will be described in connection with a preferred embodiment, it will be understood that I do not intend to limit the invention to that embodiment. On the contrary, I intend to cover all alternatives,modifications and equivalents as may be included within the spirit and scope of the invention.

Turning to the drawing, there is shown a clock containing a temperature alarm mechanism 11 but which, from the exterior, need not differ from any conventional electricclock. The clock 10, for illustrative purposes, is of the bedroom alarm type having a case 12, lens 13, twelve-hour dial l4 and stack of hands 15. The clock mechanism is-mounted on front and rear frame plates 16 and 17, respectively, which are secured within the case 12. The hands are driven by a synchronous 60-cycle motor 20, energized through a line cord and plug 21, which is coupled to the hands through conventional gearing 22 giving proper second, minute and hour hand rotational speeds.

Being an alarm clock, the mechanism includes an alarm vibrator 23 adapted to be sounded by vibration in the magnetic field of the motor and controlled by an on-off shaft 24 and a lever 25 operated by settable alarm cams driven from the motor 20.

In accordance with the invention, an alarm vibrator 30 is anchored on the frame plate 17 so as to extend, when released, into the magnetic field of the motor 20, and a temperature responsive bi-metal element 31 is anchored on the plate 17 in position to engage and hold the vibrator 30 away from the motor 20 at normal ambient temperatures. When the ambient temperature increases, the element 31 moves away from the vibrator so that the vibrator sounds an audible alarm at a predetermined temperature. In the illustrated construction, the vibrator 30 is a strip of spring steel, similar to the conventional alarm vibrator 23, whcih is anchored to the frame plate 17 through an L-shaped lug member 32. The bi-metal element 31 is U-shaped having one arm of the U anchored by a block 33 on the plate 17 and having the other arm in position to engage the vibrator 30. Preferably, stops 34 are associated with the motor 20 to hold both of the vibrators 23, 30 at proper operating distances from the motor 20.

It will be apparent that the temperature alarm is automatically resetting since a lowering of the ambient temperature will again cause the bi-metal element 31 to move against the vibrator 30 so as to disable the alarm. It is desirable to shape the element 31 so that the alarm sounds at a relatively low temperature, such as in the range of to Most fire alarm systems are tripped at much higher temperatures, being common. The lower alarm threshold allows the person warned to check and correct the abnormality before more serious damage can result and, upon' correction, the lowering temperature will automatically silence the alarm signal. Of course, the alarm mechanism 11 remains ready to-again sound the alarm upon a sufficient increase in the ambient temperature.

Those familiar with this art will appreciate that the mechanism 11 is quite simple and can be economically embodimed in any desired electric clock configuration. Since statistics show a large proportion of domestic fires in a bedroom, incorporating the alarm mechanism 11 in an otherwise conventional bedroom alarm clock produces a useful economical device/Moreover, such a clock is readily portable and can be employed by its user in temporary accommodations such as motels and the the like. Emobodiment of the mechanism 11 in akitchen wall clock is another obviously useful application since the clock would warn of any cooking mishap resulting in an increase in kitchen temperature.

I claim as my invention:

1. In a clock having a case enclosing a frame and a synchronous electric motor driving time indicating devices, a temperature alarm contained insaid case comprising, in combination, a spring steel alarm vibrator anchored on said frame so as to extend,.when-released, into the magnetic field of said motor, and a temperature responsive bi-metal element being operatively U- shaped with one arm anchored on said frame and the other arm positioned to engage and hold said vibrator away from said motor at normal ambient temperatures, said element moving away from said vibrator upon increasing ambient temperatures sothat the vibrator sounds an audible alarm at a predetermined ambient temperature.

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1. In a clock having a case enclosing a frame and a synchronous electric motor driving time iu:icating devices, a temperature alarm contained in said case comprising, in combination, a spring steel alarm vibrator anchored on said frame so as to extend, when released, into the magnetic field of said motor, and a temperature responsive bi-metal element being operatively Ushaped with one arm anchored on said frame and the other arm positioned to engage and hold said vibrator away from said motor at normal ambient temperatures, said element moving away from said vibrator upon increasing ambient temperatures so that the vibrator sounds an audible alarm at a predetermined ambient temperature. 